CIRCUIT ARRANGEMENT FOR ATTENUATING A BROADBAND BACKGROUND NOISE LEVEL AND INTERFERING SIGNALS SUPERIMPOSED THEREUPON

摘要

A circuit for attenuating broadband background noise signals and narrower band interfering signals for facilitating detection of simultaneously appearing useful signals having a shorter duration than the interfering signals, the circuit including two channels for respectively attenuating signals in the narrower band and outside the narrower band but with a broader band, with an operational amplifier connected in at least one channel and controlled to have a constant output with respect to signals of longer duration than the useful signals, the amplifier output providing the desired circuit output signal.